Process for the manufacture of artificial textile fibers



' Patent ed Jan. 11, 1944 OFFICE 2,338,920 raocnss FOB 'rnn morac'ruan or All TIFICIAL TEXTILE FIBERS Antonio Ferretti, Mllnm'ltaly; vested iii the Alien Property Custodian No Drawing. ,Application July 31, 1940, Serial No. 348,994. In Italy August 23, 1935 4 Claims.

Thisinvention concerns improvements in orrelating to processes for the manufacture of artificial textile fibers. Y

In co-pending U. S. patentapplication Serial No. 96,470, of 1936, of which this'application'is a continuation in part, processes are described and claimed by,which a casein and a colloidal solution thereof may be produced which are suitable for use in the manufacture of artificial tex- "tile fabrics. The-present invention co'ncerns the treatment of suchcasein when spinning.

According to the present invention there is provided in a process for the manufacture of artificial textile fibers, the step of passing analka= line solution of casein derived from milk through a spinning nozzle and coagulating the filaments obtained thereby in an aqueous solution 6f an acid and at least one other substance which renders the coagulated fibers insoluble. The process may be effected with the addition of aluminium salts and/or tin salts and/or formaldehyde with ortwithout sodium salts to the acid coagulating ba h.

Example of coagulating baths whichmay be employed areas follows:

Example A An aqueous solution of sulphuric acid and sodium sulphate is made, the proportions being such that the bath contains 140 cubic centimetres of 66 B. sulphuric acid and 400 grammesof sodium sulphate for each litre of the'bath. To this solution, aluminium salts are added, preferably aluminium sulphate or potash alum. It is also advantageous to add small quantities of tin salts, for example tin acetate.

Example B ence of the sodium chloridin the bath assists the action of the aluminium salts in making filaments insoluble. In preparing this solution, care should be taken not to heat it unduly, seas to avoid the transformation of a portion of the sulphuric acid into hydrochloric acid. 'lhere may 'agent.

likewise'be added to this solution small quantities, up to 10% of the solution by weight, of other salts, such as for example, magnesium sulphate, zinc sulphate, ammonium sulphate or the like in order to increase the efiiciency of the coagulation.

When the colloidal solution of casein contains carbon disulphide, it is preferable to employ the first bath indicated above as the coagulating For the mixed solutions of casein and viscose, the first bath is likewise preferable and the amount of sulphuric acidemployed can be gradually reduced to of the amountindicated above according to the higher or lower percentage of viscose added to the casein solution. 'I'he higher the percentage of viscose, the lower can be the amount of acld'in the coagulating bath. Also, the bath temperature may be slightly lower.

What I claim and desire to secure by United States Letters Patent is:

1. In a process for manufacturing artificial textile fibers from milk casein, following the spinning .of an alkaline solution of such casein, the step of coagulating the spun filaments by treatment in an aqueous acid bath, containing a salt for promoting coagulation, selected from "the group consisting of, the sulphates of sodium and magnesium and zinc and ammonium; and containing a hardening and insolubilizing agent selected from the, group consisting of aluminum sulphate and potash alum. 1

2. The process as in claim 1 and wherein the hardening and insolubilizing agent is aluminum sulphate.

3. In a process for manufacturing artificialv textile fibers from milk casein, following the spinning oLan alkaline solution of such casein, the step of coagulating the spun filaments by treatment in- .an aqueous acid bath, containing a salt for promoting coagulation, selected I from the group consisting of the sulphates of sodium and' magnesium and zinc and ammonium, and containing sodium chloride and umlnum sulphate to harden and insolubiliz'et e coagulated filaments.

4. A process for making artiflcial..,textile fibers from an alkaline solution of casein which consist in spinning filaments or thesoluble casein into an acid bath containingin each liter approximately cubic centimeters of sulphuric acid of 66 B.: from 150 to 200 grams of aluminum sulphate, approximately '15 grams of sodium chloride and a minor quantity of magnesium sulnhate.

s ANTONIO FERRE'ITL 

